JPS63222864A - Page printer control - Google Patents

Abstract

PURPOSE:To enable continuous printing, by providing a pair of code memories then comparing a writing address with a reading address, and writing print data of next page into a occupied code memory of a pair of code memories if there is a writing margin in a bit map memory. CONSTITUTION:Code memories 1a, 1b store single page print data respectively while a judging means 10 compares the writing address (vertical address YW) of a bit map memory 3 with the reading address (vertical address Yr) and judges whether there is a margin of writing into the bit map memory 3. If there is a margin, print data of next page is written into a not-yet-occupied code memory during writing cycle. Since next page print data can be prepared during single page printing operation, time necessary for storing print data into the code memory 1 upon finish of single page printing can be shortened, thereby continuous printing is enabled.

Description

[Detailed Description of the Invention] [Table of Contents] Overview Industrial Application Fields Prior Art (Figures 3 and 4) Problems to be Solved by the Invention Means for Solving the Problems (Figure 1) Effects Embodiment + al - Description of the embodiment (Figure 2) Mountain) Description of other embodiments Effects of the invention [Summary] Decrease in throughput in a banded bitmap type page printer for a fraction of a page as a bitmap memory In order to prevent this, a pair of code memories for one page is provided, and if the remaining read capacity to the bitmap memory exceeds a certain value, writing of the contents of the - code memory to the bitmap memory is stopped, and the other A device that speeds up continuous printing by writing print data into code memory.

[Industrial application field]

The present invention is a page printer control method that improves throughput when a band bitmap memory is used as a focus map memory in a page printer such as a laser printer or an LED printer.
The price of page printers such as printers and liquid crystal printers has decreased significantly.

In these printers, it is necessary to store one page's worth of print bit patterns in a bitmap memory in advance, and there are two methods for this: a full-page bitmap method and a band bitmap method.

The full page bitmap method has a bitmap memory with a capacity of one page, while the band bitmap method has a bitmap memory with a capacity of a fraction of a page.

Therefore, although the band bitmap method allows the memory capacity to be reduced and the cost to be lowered, the throughput may decrease, and improvements in this regard have been desired.

[Conventional technology]

FIG. 3 is a block diagram of a conventional page printer control unit using the band bitmap method.

In the figure, 1 is a code memory that stores print data for one page, 2 is a pattern conversion memory (means) that converts the print data in the code memory 1 into a corresponding print bit pattern, 3 4 is a bitmap memory that stores bit patterns for a fraction of a page; 4 is a control unit that is composed of a microprocessor and controls read/write of code memory 1 and read/write of the bitmap memory; It controls the write address register 40 of the code memory 1, the read address register 41, and the write vertical (
Y) A device having an address register 42, etc., and 5 a data transfer circuit which reads out the focus pattern for one line of the bitmap memory 3 in response to a periodic synchronization signal from the printing mechanism control section 9, and transfers the focus pattern to a discrete series. 6 for converting and transmitting one line of serial data to the printing mechanism control unit 9;
7 is an address switching circuit that switches between the write address side a and the read address side in response to a bus switching signal from the control unit (hereinafter referred to as MPU) 4; 7 is a data switching circuit; The data bus (B2) side a1 is switched to the read data bus (B5) side, 8 is a read address section, which has a read horizontal address register and a read vertical address register, 9 is a printing mechanism control section, In synchronization with print feed,
Recording (printing) is performed every 1947 minutes, and one line of serial data is obtained from the data transfer circuit 5 in response to a synchronizing signal.

FIG. 4 is an explanatory diagram of the prior art.

If a band bitmap memory is used, ring buffer control is used because it does not have the capacity for one page. That is, as shown in FIGS. 4(A), (B), and (C), it has vertical address pointers R and W on the read side and write side, and when both the read side and write side reach the end point of the memory 3, Use control to return to the top.

On the other hand, in the code memory 1, the print data is sorted for each line and stored as shown in FIG.
Y) The print data on the first line is the horizontal position f(X) and its character code (address of the pattern conversion memory), and the amount of data on each line varies depending on the number of characters to be printed.

In order to read and write to this bitmap memory 3, as shown in FIG. 8 to the bitmap memory 3 via the bus B4, and read data is provided to the data transfer circuit 5 via the bus B5. After incrementing the horizontal address Xr and reading one line of data, the data transfer circuit 5 performs serial-to-serial conversion on the read data and transfers it as serial data.

This transfer period after reading is used to write a pattern in the bitmap memory 3, and after the read operation of the memory 3 is completed, the MPU 4 switches the switching circuit 6.7 to a by the bus switching signal.
switch the vertical address YW from register 42 to bus B.
3, the horizontal address Ru.

In this way, reading and writing to the bitmap memory 3 are performed alternately with priority given to printing (reading (reading)), and one page is read and written by the ring buffer control shown in FIGS. 4(A), (B), and (C). A bit pattern of minutes is output.

[Problem that the invention seeks to solve]

In such conventional technology, printing starts only after one page of print data is stored in the code memory 1.

Therefore, as shown in FIG. 4(F), after writing the print data to the code memory 1, writing of the bit pattern to the bit map memory 3 and reading of the bit pattern from the bit map memory 3 are executed. 1 by reading the bit pattern for one page from memory 3.
After printing for a page is completed, the operation of writing print data for one page into the code memory 1 is performed again.

For this reason, in the conventional technology, after printing one page, printing cannot be started until writing to code memory 1 is finished, and writing to code memory 1 ends while loading the next sheet after finishing one page. Otherwise, continuous printing cannot be performed, resulting in a problem of reduced throughput, which hinders the speeding up of such band bitmap type printers.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a page printer control method that enables continuous printing by preparing data for the next page while printing one page.

[Means for solving problems]

FIG. 1 is a diagram explaining the principle of the present invention.

In Fig. 1(A), the same parts as those shown in Fig. 3 are indicated by the same symbols, and 1a and 1b are code memories, each of which can store print data for one page. , 10 is a determining means, which determines the write address (vertical address Yw) of the bitmap memory 3 and the read address (
The vertical address Yr) is compared to determine whether there is enough room for writing to the bitmap memory 3.

Then, when there is room for writing, print data for the next page is written in the code memory that is available during the write cycle.

[Effect]

The reading time to the bitmap memory 3 is constant because one line is read, whereas the writing time varies depending on the number of characters in one line, etc.

Therefore, on the bitmap memory 3, as shown in FIG.
It may change like l, dl.

The remaining read capacity is determined from the difference between the read address and the write address of the bitmap memory 3, and when there is sufficient space for writing (the remaining write capacity is large), the remaining capacity is shown in Figure 1 (B).
As shown in FIG. 3, writing of the bit pattern to the bit map memory 3 is stopped and the print data of the next page is written to the vacant code memory 1a or 1b.

Therefore, since the print data for the next page can be prepared during the printing operation of one page, the time required to store the print data in the code memory 1 after printing one page can be shortened, making continuous printing possible and increasing throughput. improves.

〔Example〕

(a) Description of one embodiment FIG. 2 is a configuration diagram of an embodiment of the present invention.

In the figure, the same parts as those shown in FIGS. 1 and 3 are indicated by the same symbols, and IQa is a deviation circuit, which is the deviation (absolute value) between the write vertical address Yw and the read vertical address Yr. 1ob is a comparison circuit that compares the deviation of the deviation circuit 10a with a predetermined value n, and if the deviation is greater than or equal to the predetermined value n, issues a margin signal to the MPU 4, 40a,
40b are write address registers,
41a and 41b are respectively read address registers that give write addresses to the code memories 1a and 1b, and 43 is a predetermined value register that provides a limit value. A certain predetermined value n is stored therein, and 11 is a memory switching circuit, which switches the connection between the pattern conversion memory 2 and the code memories 1a and 1b in response to a memory switching signal from the MPU 4.

Next, the operation of the configuration shown in FIG. 2 will be explained.

First, write the write address to the code memory 1a in the register 40.
From a, write data (print data) is applied to bus B1, and print data for one page is stored.

When printing data for one page has been stored, the memory switching circuit 11 is set to the d side by a memory switching signal, the code memory 1a and the pattern conversion memory 2 are connected, and printing is started.

That is, as mentioned above, the MPU
4 controls the serial data printing mechanism of the data transfer circuit 5 by switching the switching circuits 6 and 7 to the b side and reading out the bit pattern indicated by the read address from the bit map memory 3 to the data transfer circuit 5 according to the bus switching signal. During the transfer to the section 9, the switching circuit 6.7 is switched to the d side by the bus switching signal, and the contents of the code memory 1a are transferred to the pattern conversion memory 2.
The data is converted into a bit pattern and written to the location on the bitmap memory 3 indicated by the write vertical address Yws and the horizontal address Xw via the bus B2.

In this way, reading/writing of the bit pattern to the bit map memory 3 is repeated alternately with read priority, and the read vertical address Yr is incremented each time a data transfer end signal arrives.

On the other hand, in the determining means 10, the deviation circuit 10a calculates the deviation between the write vertical address Yw and the read vertical address Yr, and the comparison circuit tab compares the deviation with a predetermined value n of the register 43.

If writing to the bitmap memory 3 is faster than reading to the data transfer circuit 5, the difference between the amount of data written to the bitmap memory 3 and the amount of data read out (
(read remaining amount) becomes large, and the deviation becomes large.

When this deviation exceeds the predetermined value n, the comparator circuit 10b issues a margin signal to the MPU 4.

The MPU 4 thereby issues a memory switching signal, the memory switching circuit 11 is connected to the C side as shown in FIG. 2, and the connection between the code memory 1a and the pattern conversion memory 2 is cut off.

Therefore, writing of the bit pattern to the bitmap memory 3 is interrupted.

During this time, the MPU 4 provides a write address using the write address register 40b and print data from the bus B1, and stores the print data of the next page in the code memory 1b.

During this time, the switching circuits 6 and 7 are set to the b side by the bus switching signal, allowing data to be read from the bitmap memory 3 to the data transfer circuit 5 at any time.

The MPU 4 monitors the margin signal of the determiner '&10, and when the deviation (remaining readout amount) of the deviation circuit 10a becomes small and becomes less than a predetermined value n and the comparison circuit 10b no longer generates a margin signal, the MPU 4 outputs a memory switching signal. The memory switching circuit 11 is switched to the d side, and the code memory 1a and the pattern conversion memory 2 are connected again. Therefore, in the write cycle, a bit pattern corresponding to the print data in the code memory 1a is written into the bitmap memory 3.

In this way, when the printing operation for one page is completed,
The MPU 4 writes the print data of the remaining amount of the next page into the code memory 1b and starts printing.

At this time, in order to write to the bitmap memory 3, the memory switching circuit 11 switches to the C side, and the code memory 1b
and pattern conversion memory 2 are connected.

In this way, the print data for the next page can be prepared during the printing operation of one page, and the time from the end of printing one page to the start of printing the second page can be shortened.

(b) Description of another embodiment In the above embodiment, when the remaining read capacity of the bitmap memory 3 becomes large, writing of print data to the code memory 1b is performed not only in a predetermined write cycle but also in a read cycle. However, depending on the capabilities of the MPU, this may be performed only for write cycles.

Further, although the remaining read amount is determined by comparing the vertical addresses, that is, the number of lines, it may also be determined by comparing the number of bytes.

Furthermore, the bitmap memory 3 is read every byte for one raster, but for example, if 2 bytes are read and 2
A cycle may be defined such that a write is performed while a byte is being transferred.

Although the present invention has been described above using examples, the present invention can be modified in various ways according to the gist of the present invention, and these are not excluded from the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to prepare the print data for the next page during printing, so even if an inexpensive band bitmap memory is used, continuous printing is possible and throughput is improved. This greatly contributes to speeding up and lowering the cost of page printers.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the principle of the present invention, FIG. 2 is a configuration diagram of an embodiment of the present invention, FIG. 3 is a configuration diagram of a prior art, and FIG. 4 is an explanatory diagram of the prior art. In the figure, 1, 1a, 1b...code memory, 2-pattern conversion memory, 3-bit map memory, 4--control unit, 10-judgment means.

Claims (1)

[Claims] Code memory (1) that stores print data for one page
, comprising a pattern conversion means (2) for converting the contents of the code memory (1) into a bit pattern to be printed, and a bitmap memory (3) capable of storing bit patterns for a fraction of a page; A write cycle is executed to write the bit pattern to the bitmap memory (3) according to the write address, and a write cycle is executed to write the bit pattern to the bitmap memory (3) according to the read address.
) in a page printer control method in which a read cycle is executed to read out the bit pattern from the write address and the bit pattern to be printed for one page is output. A determination means (10) is provided for comparing the read addresses and determining whether there is room for writing to the bitmap memory (3), and when there is room for writing, the pair of code memories (1a, 1b) are provided. ) A page printer control method characterized in that print data for the next page is written into a vacant code memory.